Compatriot Laetitia le Corguille finished second to take the silver with American Jill Kintner taking the bronze.

Briton Shanaze Reade was in silver medal position on the final bend but the 19-year-old double world champion clipped Chausson's back wheel and crashed out of the race.

It was the last competitive race for the 30-year-old Chausson, a multiple world champion in mountain bike, who came back to her first love of BMX two years ago after it was included on the Olympic program.

"It's been a long two years of hard work, but this is definitely my last race," said Chausson, who stopped BMX when she was 13 years old to take up mountain biking.

"To finish as Olympic champion, having applied all the things we've worked on in training for this over the past two years is just amazing."

Chausson and Reade broke clear of the field going into the final bend, with the Frenchwoman pulling slightly in front of her 19-year-old rival.

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But disaster struck for Reade when her front wheel appeared to clip the back wheel of Chausson, and she came crashing down. It was her third crash in two days of racing, and left her with a hand injury.

"She must have taken the bend too tight, and then I felt her clipping my back wheel," said Chausson, who had been unaware she was in a duel for the gold medal.

It was also Reade's first defeat in a final since she was 16, but she has promised to come back to fight for gold at London in 2012. "I guess they say you learn the hard way, and today I've learned the hard way," said Reade. "I am hurting. I think I broke my hand as well."

Meanwhile, Maris Strombergs of Latvia kept his nerve in the face of a two-pronged American challenge to win gold in the men's BMX final.

The silver medal went to Mike Day with the bronze to his fellow-American Donny Robinson.

Strombergs staked his claim for gold when he sailed through qualifying and won all three of his semifinal runs to secure his place in the final.

After the first bend and first jumps took an early toll on the field, Strombergs took the lead at the halfway point before the crucial big jump leading into the penultimate straight.

It was there that Jared Graves of Australia, sitting just behind the Latvian, saw his chances bite the dust when he was brought down by the flying bike of crashing South African Sifiso Nhlapo.

Strombergs, who has been racing BMX bikes for 16 years, then stretched his advantage heading into the final bend and was never really challenged by Day or Robinson. "I really didn't have a gameplan," said Strombergs, who won the world title earlier this year. "I just raced my race and it came out for the best."

Elsewhere on day 15 of the Games, China's world number one Zhang Yining won back-to-back table tennis golds, after defeating team-mate Wang Nan to hand the hosts a clean sweep of the medals in the women's singles.

A composed and confident Zhang fought back from one game down against the retiring veteran Wang, winning 8-11, 13-11, 11-8, 11-8, 11-3 in a battle of the giants of the sport.

The win hands Zhang her fourth gold medal over two Olympics, after success in the women's singles and doubles in Athens and team and singles competition in Beijing, equally the great Deng Yaping's gold medal haul.

For Wang, the loss means the 29-year-old retires from the sport without winning another gold to add to her collection of four over three Olympics.

China, where millions play table tennis across the country, have never lost the women's singles crown since the sport was introduced at the 1988 Olympics.

They also have a chance to clean sweep all of the medals on the men's side, with Sweden's Jorgen Persson the only player left to halt the powerful trio led by world number one Wang Hao in the semifinals on Saturday.

Meanwhile, The Netherlands defeated China 2-0 to win the gold in women's field hockey. The Dutch won silver at the 2004 games in Athens, but had not won gold since 1984.

The sixth-ranked Chinese held their own against the world's top-ranked team, but lacked the skill to match the Dutch. Argentina defeated Germany 3-1 to win the bronze medal, a repeat of their 2004 finish.

Todd Rogers and Phil Dalhausser completed an American sweep of the beach volleyball gold medals, beating Brazil in three sets.

A day after Kerri Walsh and Misty May-Treanor weathered a driving rainstorm to win their second straight gold, the men won their Olympic debuts in more typical beach weather 23-21 17-21 15-4.

Six gold medals were decided in canoeing, with Attila Vajda of Hungary winning the men's 1,000 meter singles in 3:50.46, taking a step up on the podium after his bronze four years ago in Athens.

Defending champion David Cal of Spain won silver in 3:52.75, while Canadian Thomas Hall took the bronze medal in 3:53.65.

Andrei and Alexandr Bahdanovich of Belarus won gold in the men's 1,000 meter doubles, storming from behind to edge Germany in a thrilling finish.

The Bahdanovich brothers were nearly one second behind with 250 meters to go, but furiously paddled their way to the front just before the finish to win in 3:36.36.

The German pair of Christian Gille and Thomasz Wynlenzek, who led almost the entire way, claimed the silver with Hungarians Gyorgy Kozmann and Tamas Kiss in bronze.

Tim Brabants of Britain has won the men's 1,000-meter kayak singles, returning to the podium for the first time in eight years.

Brabants, who won bronze in Sydney in 2000, took the lead at about the halfway mark and surged ahead to win in 3:26.32 seconds.

Defending champion Eirik Veraas Larsen of Norway took home the silver medal in 3:27.34, while Australian Ken Wallace won bronze in 3:27.48.

Germany won gold in the men's 1000m Kayak doubles. The silver medal went to Denmark and the bronze to Italy.

Germany also won the gold medal in the women's500m Kayak fours from Hungary in silver and Australia in bronze, while Belarus won gold in the men's 1000m Kayak fours. The silver medal went to Slovakia and the bronze to Germany.

Lena Schoneborn of Germany won the gruelling women's modern pentathlon competition from Britain's Heather Fell, with Victoria Tereshuk of the Ukraine taking the bronze medal.

Schoneborn was the third winner of an event, which has only been a women's Olympic sport for eight years, after Britain's Stephanie Cook (Sydney 2000) and Zsuszanna Voros of Hungary (Athens 2004).